Correct Option: D

The Golconda fort used to have a vault where once the famous Kohinoor and Hopediamonds were stored along with other diamonds. Golconda was once renowned for the diamonds found on the south-east at Kollur Mine near Kollur (modern day Guntur district), Paritala (modern day krishna district) and cut in the city during the Kakatiya reign. At that time, India had the only Known diamond mines in the world.